Where can I find HAM forum, newsgroup, discussion, chat room, etc., either formal or light hearted, apart from this one?
QRZ.com has forums, news postings, classifieds and similar to what you are looking for.
radioreference.com has forums, news, and similar with lots of Amateur discussion, but is not strictly Amateur specific. You can learn a lot from this site.
There are many more to be found on the Google and you are likely to find some that are more appealing to you than others.